From: Yu Kuai <yukuai3@xxxxxxxxxx>
read_balance() will avoid reading from slow disks as much as possible,
however, if valid data only lands in slow disks, and a new normal disk
is still in recovery, unrecovered data can be read:
raid1_read_request
read_balance
raid1_should_read_first
-> return false
choose_best_rdev
-> normal disk is not recovered, return -1
choose_bb_rdev
-> missing the checking of recovery, return the normal disk
-> read unrecovered data
Root cause is that the checking of recovery is missing in
choose_bb_rdev(). Hence add such checking to fix the problem.
Also fix similar problem in choose_slow_rdev().
Fixes: 9f3ced792203 ("md/raid1: factor out choose_bb_rdev() from read_balance()")
Fixes: dfa8ecd167c1 ("md/raid1: factor out choose_slow_rdev() from read_balance()")
Reported-and-tested-by: Mateusz Jończyk <mat.jonczyk@xxxxx>
Closes: https://lore.kernel.org/all/9952f532-2554-44bf-b906-4880b2e88e3a@xxxxx/
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
---
drivers/md/raid1.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 531ddfc6efbd..1a45003ea7ee 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -617,6 +617,12 @@ static int choose_first_rdev(struct r1conf *conf, struct r1bio *r1_bio,
return -1;
}
+static bool rdev_in_recovery(struct md_rdev *rdev, struct r1bio *r1_bio)
+{
+ return !test_bit(In_sync, &rdev->flags) &&
+ rdev->recovery_offset < r1_bio->sector + r1_bio->sectors;
+}
+
static int choose_bb_rdev(struct r1conf *conf, struct r1bio *r1_bio,
int *max_sectors)
{
@@ -635,6 +641,7 @@ static int choose_bb_rdev(struct r1conf *conf, struct r1bio *r1_bio,
rdev = conf->mirrors[disk].rdev;
if (!rdev || test_bit(Faulty, &rdev->flags) ||
+ rdev_in_recovery(rdev, r1_bio) ||
test_bit(WriteMostly, &rdev->flags))
continue;
@@ -673,7 +680,8 @@ static int choose_slow_rdev(struct r1conf *conf, struct r1bio *r1_bio,
rdev = conf->mirrors[disk].rdev;
if (!rdev || test_bit(Faulty, &rdev->flags) ||
- !test_bit(WriteMostly, &rdev->flags))
+ !test_bit(WriteMostly, &rdev->flags) ||
+ rdev_in_recovery(rdev, r1_bio))
continue;
/* there are no bad blocks, we can use this disk */
@@ -733,9 +741,7 @@ static bool rdev_readable(struct md_rdev *rdev, struct r1bio *r1_bio)
if (!rdev || test_bit(Faulty, &rdev->flags))
return false;
- /* still in recovery */
- if (!test_bit(In_sync, &rdev->flags) &&
- rdev->recovery_offset < r1_bio->sector + r1_bio->sectors)
+ if (rdev_in_recovery(rdev, r1_bio))
return false;
/* don't read from slow disk unless have to */
--
2.39.2
